From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vasily Averin Subject: [PATCH v3 16/16] memcg: enable accounting for ldt_struct objects Date: Thu, 22 Apr 2021 13:38:01 +0300 Message-ID: <94dd36cb-3abb-53fc-0f23-26c02094ddf4@virtuozzo.com> References: Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=virtuozzo.com; s=relay; h=Content-Type:MIME-Version:Date:Message-ID:Subject :From; bh=VcNEmagbjV3FxnKA/CUYG6RcP5nAKSlATTz2VbvDMWI=; b=OSOsz/71WhiY0W6sqvl OqW9GKKjhDyG2qwTVH4k1T/xiF8sAiWnPp6+fj6fv2mAgm3RjZA13QGTjm5IiRBB/OsmaUYpTKdRW XVrAMx9nvnupiiim7UA9V7lROEiowza5yVNpg/zrlDELd1dHiTPZyrLmwepUwffti78K/6CeXHU= In-Reply-To: Content-Language: en-US List-ID: Content-Type: text/plain; charset="us-ascii" To: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Michal Hocko , Shakeel Butt , Johannes Weiner , Vladimir Davydov Cc: Roman Gushchin , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" Each task can request own LDT and force the kernel to allocate up to 64Kb memory per-mm. There are legitimate workloads with hundreds of processes and there can be hundreds of workloads running on large machines. The unaccounted memory can cause isolation issues between the workloads particularly on highly utilized machines. It makes sense to account for this objects to restrict the host's memory consumption from inside the memcg-limited container. Signed-off-by: Vasily Averin --- arch/x86/kernel/ldt.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c index aa15132..a1889a0 100644 --- a/arch/x86/kernel/ldt.c +++ b/arch/x86/kernel/ldt.c @@ -154,7 +154,7 @@ static struct ldt_struct *alloc_ldt_struct(unsigned int num_entries) if (num_entries > LDT_ENTRIES) return NULL; - new_ldt = kmalloc(sizeof(struct ldt_struct), GFP_KERNEL); + new_ldt = kmalloc(sizeof(struct ldt_struct), GFP_KERNEL_ACCOUNT); if (!new_ldt) return NULL; @@ -168,9 +168,10 @@ static struct ldt_struct *alloc_ldt_struct(unsigned int num_entries) * than PAGE_SIZE. */ if (alloc_size > PAGE_SIZE) - new_ldt->entries = vzalloc(alloc_size); + new_ldt->entries = __vmalloc(alloc_size, + GFP_KERNEL_ACCOUNT | __GFP_ZERO); else - new_ldt->entries = (void *)get_zeroed_page(GFP_KERNEL); + new_ldt->entries = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); if (!new_ldt->entries) { kfree(new_ldt); -- 1.8.3.1